Piano action



Dec. 16, 1941. L. M. MARTIN PIANO ACTION Filed July 15, 1940 BY 0W A TTORNEYS Patented Dec. 16, 1941 UNITED STATES PATENT OFFICE PIANO ACTION Lloyd Miller Martin, San Francisco, Calif.

Application July 15, 1940, Serial No. 345,602

Claims.

This invention relates to piano actions, and while features of the invention may be employed in the construction of a piano action for any type of upright piano, the invention is expected to be particularly useful when applied in the construction of a piano action for a spinet type piano. In this type of piano it is desirable to reduce as much as possible the distance from the keyboard to the rear wall of the piano case. Piano actions as heretofore constructed have been more or less complicated by the inclusion of many parts.

A principal object of this invention is to provide a piano action of very simple construction, having few parts, and which is particularly adapted for use in the spinettype of piano because it requires a relatively small space in the piano in the front-and-rear plane.

As ordinarily constructed, the parts of a piano action are not readily accessible for adjustment, and their construction is usually such that before the action can be lifted out of the case it must be disconnected from the actuating key. Furthermore, as usually constructed, the means for regulating the set-oif and the back check have been inaccessible.

One of the objects of the present invention is to overcome this difiiculty and to provide a construction which will enable the action to be lifted out without necessitating any disconnection being made from its actuating key; also to provide a construction for the action, which will enable the regulation of the back check and the set-off to be attained Without necessitating the removal of the action from the piano, but merely by removing the actuating key for the action.

A further object of the invention is to provide a construction whereby the movement of the key can be imparted directly to the jack so as to impart a direct blow to the hammer.

A further object of the invention is to simplify the general construction of piano actions, and particularly such an action as applied to a spinet type piano. Also to provide simple means for counterbalancing the weight of the abstract. L

the hammer back to the hammer rail. These bridle straps are of flexible material and are often destroyed by mice that have access to the interior of the piano. Although this bridle strap is objectionable, it is necessary to employ it in most actions to start the hammer back quickly toward its rest position. They are particularly necessary where the soft pedal is in operation and repeat notes are being struck. These straps have leathers at their ends which sometimes make a noise in operation. One of the objects of my invention is to avoid the necessity for employing these bridle straps, and to provide a construction in which the weight of the abstract and attached parts is exerted to effect the quick return of the hammer toward its rest position.

A further object of the invention is to provide a construction operating in such a way that when the hammer is moved forwardly, the tension of the hammer spring is not increased. This prevents any increase of resistance by the spring when the hammer advances. At the same time, in accomplishing this object, I also aim to provide a construction in which the release of the key will enable the abstract of the action to apply a force through the hammer spring to quickly return the hammer to the hammer rail.

Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combination of parts to be described hereinafter, all of which contribute to produce an efficient piano action.

A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claims.

In the drawing:

Fig. 1 is a side elevation and partial section taken through a piano action embodying my invention, and indicating the rear end of the key broken away. This View shows the action in the position of rest.

Fig. 2 is a view similar to Fig. l, but showing the parts in the relation they have when the hammer is resting against the back check, as when the key is held down.

Before proceeding to a more detailed description of the invention, it should be stated that one of its novel features is the provision of an abstract, which is offset rearwardly at its lower portion so that its lower end is located substantially below the butt of the key hammer. By accomplishing this I am enabled to attach the jack directly to the abstract so that the blow on the key is imparted directly to the jack through the abstract. The abstract is preferably in the form of an elongated bar, the lower portion of which is offset or bent rearwardly toward the jack position, and so as to lie almost directly below the hammer butt.

Another novel feature consists in constructing the abstract in such a way that it presents a shoulder torest on an adjustable connection such as a capstan screw at the rear end of the actuating key. This enables the action to be removed without necessitating making any disconnections from the keys.

Another novel feature of my invention is that I provide means for effecting a quick return of the hammer from its striking position that avoids the necessity of employing the objectionable bridle straps referred to above.

The parts are also constructed so that the back i check is carried at an intermediate point on the length of the abstract, with the regulating means for the back checklocated on the forward side of the abstract, and in a position such that it is accessible for regulation merely by lifting out the key for the action.

Referring more particularly to the parts, 1 indicates the action rail on which the butts 2 of the hammers 3 are pivotally mounted to swing in a rear direction to strike the piano strings at 4. In .accordance with my invention, I provide means whereby the hammer butt can be actuated through the medium of a jack 5 to which movement is imparted directly from the rear end of the key 6 through the medium of the abstract 1. In order to accomplish this, the abstract is provided with a shoulder 8 which rests on an adjustable connection such as a capstan screw 9 on the rear end of the key. This shoulder 8, in the present instance, is illustrated as forming the under side of a head [0 on the abstract that projects forwardly from the shank ll of the abstract, which shank extends downwardly in a substantially vertical position beyond the rear end of the key, and merges into the body portion I2 of the abstract or sticker, which is offset rearwardly preferably in a curved line as indicated, so that its lower end is located below and nearly under the hammer butt 2. V

Means are providedfor guiding the lower end of the abstract, and also for guiding its upper end near the hammer rail I3. In order to accomplish this, I prefer to employ a whippen l4 pivotally. mounted at IS on the under side of the action rail 1 This whippen projects toward the front of the piano and is preferably provided with a slot iii in which the lower end of the abstract is mounted on a pivot pin I71. Adjacent to this point thelower end of the jack 5 is pivotally supported and, if desired, this may be accomplished by forming a slot IS in the lower end of the abstract in which the jack is pivotally attached on the pivot pin l9. This enables the jack to rock on a single axis on theabstract. Any suitable means maybeprovided for guiding the upper end of the abstract in a substantially vertical direction when it is raised by the key that is struck. .For this purpose a link 2!] may be provided that is supported on a pivotat the rearside of the hammer rail I3,.the forward end of the link being attached in a slot 2! by means of a pivot pin 22 on the abstract. The hammer butt 2 is pivotally supported on a pivot pin 23 carried on the, action rail I, and .is formed with a curved shoulder 24 and jack pad 25 against which the end of the jack 5 thrusts. The hub 2 is also provided with means for cooperating with the back-check 26, said back-check being preferably constructed in the form of a lever mounted on a pivot pin 21 in a slot 23 formed in the abstract opposite to, and slightly below, the hammer butt. The upper side of the check lever 26 is formed with a curved back check pad 29, which cooperates with a curved pad 33 carried on a bill 3| that projects forwardly from the forward side of the hammer butt. In this way a deep slot or throat 32 is formed in the forward edge of the hammer butt, into which the rear end of the back check extends. The hammer butt carries a countemaalance spring 33 that exerts its force against the tail 34 of the back check and holds the same normally against the regulating button 35, which is provided with the usual pad 36. In other words, the tail 34 of the back check projects outwardly on the forward side of the abstract, and the position of this button 35 may be regulated by means of an adjusting screw 31 threaded into a bracket or block 38 projecting forwardly from the abstract. The upper end of this adjusting screw 31 is formed with a flat head 39 or similar means, for rotating the screw readily from a position above the same.

The jack 5 is provided at its lower end with a set-01f heel 40, the rounded nose of which is adapted to strike against an adjustable set-off button 4|, when the hammer head 3 has arrived at a point near the string 4. Between the set-off heel 43 and the outer end of the whippen M, a coil spring 42 is provided. This spring performs the regular function of a jack spring, and also assists in returning the whippen M to its extreme low, or starting position. The free end of the whippen 14 may be provided with a counterweight 43 if desired, to assist its return to starting position.

The tail end of the whippen H3 may be provided with means for actuating the damper lever A l in the usual manner to lift the damper 45 off of the strings when they are struck (see Fi 2). V

The set-off button 4| is mounted adjustably like the back check button 35, being carried on an adjusting screw 46 that is threaded into a rail 41 that extends longitudinally within the piano and transversely to the abstracts.

The throat or slot construction 32 for receiving the rear end of the back check lever, enables the abstract to be located quite closely to the hammer, but at the same time, without interfering with any of the necessary swinging movements of the hammer butt.

The hammer butt 2 may be provided with a rest pad 48 that limits the forward swinging movement of the jack underthe action of its spring 42, and in order to provide clearance for this rest pad 48, the rear edge of the jack 5 near its tip may be provided with a, clearance notch 49. If desired, the rail l3 may be a divided rail including a forward section l3a that carries the pad for the hammer shanks, and which can be moved forward by the soft pedal.

In the operation of the action, when the outer end ,of the key is struck, the inner or rear end 6, of course, rises in the usual manner. The force striking the key is imparted by the capstan screw 9 to the upper end of the abstract 1, which immediately rises and pulls up the lower end of the jack 5, striking a direct blow to the hammer. The thrust of the jack against the butt or hub of the hammer, swings it toward the string 4, and when the hammer head is near the string, the setoff button 4| engages the set-off heel 40 and throws the upper end of the jack out of driving contact with the pad 25.

If the key is held down after being struck, the hammer will rebound to the back check position indicated in Figure 2. This back check position can be regulated, of course, by adjusting the screw 31. If it is necessary to remove the action, this can be accomplished by disconnecting the brackets (not illustrated) to which the rails are attached, and the action can then be lifted out. This is possible by reason of the fact that there is no connection between the abstract heads 10 and the screws 9 except an operating contact.

The back check position can be regulated Without taking the action out of the piano, by simply removing the key and then inserting a jack regulating tool with a long stem, through the gap or space 50 between the key rest 5| and the shanks I I of the abstracts.

It is also possible to adjust the set-oil button 4| in the same way by using a jack regulating tool.

The spring 33 operates as a hammer spring, imparting the weight of the abstract to the hammer butt. This accelerates the return of the hammer to its rest position and results in a particularly efficient action when repeat notes are being struck while applying the soft pedal. It

eliminates the use of the flexible bridle strap commonly employed in upright actions. This spring also operates as a spring for the back check to hold it against the back check button 35. The capstan screw 9 should be adjusted so that it will just touch the shoulder pad 8. Hence in striking the key it is merely necessary to overcome the inertia of the abstract when imparting the drive to it.

In connection with the operation of the spring 33, it should be understood that as the hammer swings toward the piano string 4 the abstract is rising, and as the abstract rises the spring 33 slides toward the rear on the under side of the back check. By reason of the rising movement of the abstract there is practically no increase in tension of the spring 33. Furthermore, by reason of the fact that the spring 33 is attached to the hammer butt between the abstract and the pivot 23 for the hammer butt, it will be evident that when the key is released the Weight of the abstract and its connecting parts is imparted to the spring 33, and the force exerted at the point of attachment of the spring to the hammer butt is in a direction to give a quick acceleration of the hammer back toward its position of rest, or toward its back-check position if the key is held down.

Of course, when the action is in operation, the rear end of this spring slides along forwardly on the under side of the back check lever.

Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.

What I claim is:

1. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, a jack, an abstract comprising an elongated bar disposed in a substantially vertical position with its upper end operatively connected with the rear end of the key to enable the abstract to be raised when the forward end of the key is struck, said abstract being offset below in a downward and rearward direction toward the jack, and a pivot connection connecting the lower end of the abstract directly to the jack to rock about a single axis of rotation.

2. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, a jack, an abstract having an elongated bar extending downwardly back of the rear end of the key, and having a head extending over the rear end of the key so as to enable the abstract to be raised by the rear end of the key when the key is struck, said abstract being offset below in a downward and rearward direction toward the jack, and a single pivot connection for connecting the lower end of the abstract directly to the jack.

3. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, a jack for actuating the hammer, an abstract having an elongated bar extending downwardly adjacent the rear end of the key, adjustable means between the key and the upper end of the abstract enabling the key to actuate the same, said abstract having its body portion located below the key and offset in a downward and rear direction toward the jack, a pivot for pivotally connecting the lower end of the abstract directly to the jack, and set-off means associated with the jack for setting off the jack when the hammer head has swung forward to a point near the string. I

4. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, a jack for actuating the hammer, an abstract having an elongated bar extending downwardly adjacent the rear end of the key, a capstan screw carried at the rear end of the key, said abstract having a shoulder at its upper end resting on the capstan screw and having a body portion below the level of the key offset in a downward and rear direction toward the jack, a pivotal connection for pivotally connecting the lower end of the abstract directly to the jack, means for guiding the abstract when the same is actuated by striking the key, a spring associated with the jack, and setofi means cooperating with the jack for setting off the jack when the hammer head has arrived at a point near the string.

5. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, a jack for actuating the hammer, an abstract having an elongated bar extending downwardly adjacent the rear end of the key, adjustable means between the key and the upper end of the abstract enabling the key to actuate the same, and a whippen supported below the hammer butt connected to the lower end of the abstract, said jack pivotally supported directly on the abstract adjacent the connection point for the abstract and the whippen.

6. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, a jack, an abstract comprising an elongated bar disposed in a substantially vertical position with its upper end operatively' connected with the rear end of the key to enable the abstract to be raised when the forward end of the key is struck, said abstract being offset below in a downward and rearward direction toward the jack, a pivotal connection for connecting the lower end of the abstract directly to the jack, and a back check for the hammer supported on the abstract.

7. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, a jack, an abstract comprising an elongated bar disposed in a substantially vertical position with its upper end operatively connected with the rear end of the key to enable the abstract to be raised when the forward end of the key is struck, said abstract being offset below in its body in a downward andrearward direction toward the jack, a pivotal connection connecting the lower end of the abstract directly to the jack, and a back-check for the hammer supported on the rearwardly offset portion of the abstract, with means located on the forward side of the abstract, for adjusting the same from above when the key has been removed.

8. In a piano action, the combination of a key,

a hammer having a pivotally mounted butt for striking the piano string, an abstract disposed in a substantially vertical position with its upper end adjacent the rear end of the key and connected directly with the same to enable the abstract to be raised when the forward end of the key is struck, the lower end of said abstract located below the hammer butt, means for guiding the lower end of the abstract, a jack supported by the lower end of the abstract for engaging the hammer butt to thrust upwardly to actuate the same, a back-check pivotally mounted on the abstract at about the level of the hammer butt, said hammer butt having a part to cooperate with the back-check when the key is struck and held down. 9. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, an abstract comprising an elongated bar disposed in a substantially vertical position with its upper end operatively connected with the rear end of the key to enable the abstract to be raised when the forward end of the key is struck, the lower end of said abstract located below the hammer butt, a hammer rail having a rest for the hammer, means for guiding the lower end of the abstract, a jack supported by the lower end of the abstract for engaging the hammer butt to thrust upwardly against the same, means for guiding the upper end of the abstract adjacent the hammer rail, a back check, and means for connecting the middle portion of the abstract to the back-check.

10. In a piano action, the combination of a key, a hammer having a pivotally mounted butt, for striking the piano string, an abstract disposed in a substantially vertical position with its upper end adjacent the rear end of the key and connected with the same to enable the abstract to be raised when the forward end of the key is struck, the lower end of said abstract located below the hammer butt, means for guiding the lower end of the abstract, a jack supported by the lower end of the abstract for engaging the hammer butt to and thrusting upwardly against the hammer butt to actuate the same, a backcheck lever pivotally mounted on the abstract at about the level of the hammer butt with its tail end extending forward from the abstract, and an adjustable stop on the forward side of the abstract adjustable from above for adjusting the position of the back-check, said hammer butt having an extension to cooperate with the back-check when the key is struck and held down.

11. In a piano action, the combination of a key, a hammer having a pivotally mounted butt, for striking the piano string, an abstract disposed in a substantially vertical position with its upper end adjacent the rear end of the key and connected with the same to enable the abstract to be raised when the forward end of the key is struck,'the lower end of said abstract located below the hammer butt, means for guiding the lower end of the abstract, a jack supported by the lower end of the abstract for engaging the hammer butt and thrusting upwardly to actuate the same, a back-check lever pivotally mounted on the abstract at about the level of the hammer butt with its tail end extending forward from the abstract, an adjustable stop on the forward side of the abstract adjustable from above for adjusting the position of the back-check, said hammer butt having an extension to cooperate with the back-check when the key is struck and held down, and a hammer spring carried by the hammer butt with its free end operating to slide along the under side of the back-check, yieldingly holding the back-check against the adjustable stop.

12. In a piano action, the combination of a key, a hammer movably mounted to strike the piano string, an abstract comprising an elongated bar disposed in a substantially vertical position with its upper end operatively connected with the rear end of the key to enable the abstract to be raised when the forward end of the key is struck, said abstract being offset below in a downward and rearward direction toward the jack, and extending below the level of the hammer butt, means for connecting the lower end of the abstract directly to the jack, so that the jack thrusts upwardly against the hammer butt, a back-check pivotally carried on the abstract, an adjustable stop therefor, and a hammer spring carried by the hammer and engaging the back-check to hold the same against the stop.

13. In a piano action, the combination of a hammer having a butt pivotally supported, a hammer rail for supporting the hammer in its position of rest, an abstract located adjacent the hammer, means actuated by the lower end of the abstract for engaging the hammer butt to swing the hammer, a spring for counterbalancing the abstract, a key for imparting the striking force to the abstract, rest means for holding the action in a state'of rest, said abstract having a shoulder adjacent the rear end of the key, and said key having adjustable means capable of being adjusted so that it will substantially touch the said shoulder when the action and the key are at rest.

14. In a piano action, the combination of a hammer having a butt pivotally supported, a hammer rail for supporting the hammer in its position of rest, an abstract located adjacent the hammer, means actuated by the lower end of the abstract for engaging the hammer butt to swing the hammer, a hammer spring mounted on the hammer butt for counterbalancing the abstract, a key with a capstan screw for imparting the striking force to the abstract, said abstract having a shoulder adjacent the rear end of the key to engage the capstan screw, and means for holding the action in a state of rest in which the capstan screw will substantially touch the said shoulder when the abstract and the key are at rest.

15. In a piano action, the combination of a hammer having a butt pivotally supported, a hammer rail for supporting the hammer in its position of rest, an abstract located adjacent the hammer, means actuated by the lower end of the abstract for engaging the hammer butt to swing the hammer, a back check in the form of a lever pivotally mounted on the abstract and 2,266,690 5 projecting toward the hammer butt for coopto accelerate its return toward the rest position, eration with the same to hold the hammer in and a key for imparting the striking force to its rebound position, a spring carried by the the abstract, said key having adjustable means hammer butt and exerting its force on the under for imparting the striking movement to the side of the back check and operating to impart 5 abstract. the weight of the abstract to the hammer butt LLOYD MILLER MARTIN. 

